Temperature Optimized Hydrolysis of Acetic Acid Catalyzed Magnesium Hydride for Hydrogen Generation in a Batch System Hydrogen Reactor

Interests in hydrogen storage in magnesium hydride (MgH₂) is ongrowing due to its high gravimetric and volumetric hydrogen concentration and less harmful environmental impact of its reaction. This study reports the usage of acetic acid as an accelerator in hydrogen generation experiment via hydrolysis, using a batch system hydrogen reactor. The study was conducted in two phases: investigation of role of substrate weight and catalyst concentration on hydrogen yield and optimization of temperature for hydrogen generation. The study investigated the roles of the organic acids in the reduction of the poor reaction kinetics limitation in MgH₂ through the catalytic characteristic of acetic acid. Three acetic acid concentrations were used in the study namely 40, 50 and 60 wt%. Similarly, three substrate weights (0.4, 0.8 and 1.2 g) were investigated for the role of substrate weight on hydrogen yield. Application of the acetic acid accelerated the hydrogen yield across board. Similarly, the hydrogen yield increased with MgH₂ weight in the study. The highest hydrogen yield of 0.0189 L was recorded from 1.2 g MgH₂ at 30 °C and 50 °C respectively and 50 wt% acetic acid. The lowest hydrogen yield in the study was 0.0048 L hydrogen gas from 0.4 g MgH₂ at 50 wt% acetic acid. The experiment conducted at ambient temperature (25 °C) revealed comparable hydrogen yield with higher temperatures.